“Because, mon ami , it is the law of your country that a man once acquitted can never be tried again for the same offence. Aha! but it was clever⁠—his idea! Assuredly, he is a man of method. See here, he knew that in his position he was bound to be suspected, so he conceived the exceedingly clever idea of preparing a lot of manufactured evidence against himself. He wished to be arrested. He would then produce his irreproachable alibi⁠—and, hey presto, he was safe for life!”

“But I still don’t see how he managed to prove his alibi, and yet go to the chemist’s shop?”

Poirot stared at me in surprise.

“Is it possible? My poor friend! You have not yet realized that it was Miss Howard who went to the chemist’s shop?”

“Miss Howard?”